package com.xuan.juc.pc;

import java.util.Date;

/*
* 线程之间的通讯问题：生产者和消费者问题！
* 线程交替执行 A B 操作同一个变量 num=0
* A num+1
* B num-1
*
* */
public class providerCustomer {
    public static void main(String[] args) {
        Data data = new Data();
        new Thread(()->{
            for (int i = 0; i < 10; i++) {
                try {
                    data.increment();
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
        },"A").start();
        new Thread(()->{
            for (int i = 0; i < 10; i++) {
                try {
                    data.decrement();
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
        },"B").start();
        new Thread(()->{
            for (int i = 0; i < 10; i++) {
                try {
                    data.decrement();
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
        },"C").start();
        new Thread(()->{
            for (int i = 0; i < 10; i++) {
                try {
                    data.decrement();
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
        },"D").start();
    }
}


// 资源类
// 等待 业务 通知
class Data{
    private int num = 0;

    public synchronized void increment() throws InterruptedException {
        while(num!=0){
            // 等待
            this.wait();
        }
        num++;
        System.out.println(Thread.currentThread().getName()+"=>"+num);
        // 通知其他线程 +1完毕
        this.notifyAll();
    }

    public synchronized void decrement() throws InterruptedException {
        while (num==0){
            // 等待
            this.wait();
        }
        num--;
        System.out.println(Thread.currentThread().getName()+"=>"+num);
        // 通知其他线程 -1完毕
        this.notifyAll();
    }
}
